Spring manufacturing apparatus

ABSTRACT

Tool units ( 400 ) are slid by crank mechanisms ( 409 ) which are arranged on the respective sides of a table ( 200 ), convert rotational motions into translational motions, and use servo motors as drive sources, and are supported to swing on the rear end portions of the tool units.

FIELD OF THE INVENTION

[0001] The present invention relates to a spring manufacturing apparatusfor manufacturing springs having various shapes by forcibly bending,curving, or winding wires to be formed into springs with tools whilecontinuously feeding the wires.

BACKGROUND OF THE INVENTION

[0002] In a conventional spring manufacturing apparatus, tools arerespectively driven/controlled by independent servo motors and placed atarbitrary angles around a wire.

[0003] The tool positions are, however, finely adjusted by a skilledoperator by hunching in accordance with a desired spring shape. Thisoperation is difficult to repeat, and hence is a most time-consumingoperation.

SUMMARY OF THE INVENTION

[0004] The present invention has been made in consideration of the aboveproblem, and has as its object to provide a spring manufacturingapparatus which can execute fine adjustments on the positions of aplurality of tools with respect to the wires fed out from the wireguides by automatic control with high accuracy in a short period oftime.

[0005] In order to solve the above problem and achieve the above object,according to the present invention, there is provided a springmanufacturing apparatus for manufacturing a spring by feeding a wire tobe formed into a spring out of an end portion of a wire guide, andforcibly bending, curving, or winding the wire by using a tool in aspring forming space near an end portion of the wire guide, wherein aplurality of tools arranged to extend radially with respect to wires fedinto the spring forming spaces, supported to be slidable toward thewires fed into the spring forming spaces, and supported to allow the endportions of the tools to simultaneously swing with respect to the wiresfed out from the end portions of the wire guides.

[0006] As described above, according to the present invention, since aplurality of tools are supported to allow the end portions of the toolsto simultaneously swing with respect to the wires fed out from the endportions of wire guides, fine adjustments on the positions of aplurality of tools with respect to the wires fed out from the wireguides can be simultaneously executed by automatic control with highaccuracy in a short period of time.

[0007] Other features and advantages of the present invention will beapparent from the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a perspective view showing the outer appearance of aspring manufacturing apparatus according to an embodiment when viewedfrom the front side;

[0009]FIG. 2 is a perspective view showing the outer appearance of thespring manufacturing apparatus according to this embodiment when viewedfrom the rear side;

[0010]FIG. 3 is a front view showing the spring manufacturing apparatusaccording to this embodiment;

[0011]FIG. 4 is a rear view showing the spring manufacturing apparatusaccording to this embodiment;

[0012]FIG. 5 is a side view showing the spring manufacturing apparatusaccording to this embodiment;

[0013]FIG. 6 is a perspective view showing the outer appearance of acurving tool unit;

[0014]FIG. 7 is a plan view showing the curving tool unit;

[0015]FIG. 8 is a side view showing the curving tool unit;

[0016]FIG. 9 is a perspective view showing the outer appearance of arotating tool unit;

[0017]FIG. 10 is a plan view showing the rotating tool unit;

[0018]FIG. 11 is a side view showing the rotating tool unit;

[0019]FIG. 12 is a perspective view showing the outer appearance of atable including a swing ring;

[0020]FIG. 13 is a front view showing the swing ring;

[0021]FIG. 14 is a plan view showing a driving mechanism for the swingring;

[0022]FIG. 15 is a sectional view taken along a line I-I in FIG. 14;

[0023]FIG. 16 is a view showing rotating tool bending in two-dimensionalforming;

[0024]FIG. 17 is a view showing rotating tool bending in two-dimensionalforming;

[0025]FIG. 18 is a view showing tool bending in two-dimensional forming;

[0026]FIG. 19 is a view showing tool bending in two-dimensional forming;

[0027]FIG. 20 is a view showing a rotating tool winding process inthree-dimensional forming;

[0028]FIG. 21 is a view showing the rotating tool winding process inthree-dimensional forming;

[0029]FIG. 22 is a view showing a coiling process in three-dimensionalforming;

[0030]FIG. 23 is a view showing the coiling process in three-dimensionalforming;

[0031]FIG. 24 is a view showing a pitched coiling process inthree-dimensional forming;

[0032]FIG. 25 is a view showing the pitched coiling process inthree-dimensional forming;

[0033]FIG. 26 is a view showing a hook raise process inthree-dimensional forming;

[0034]FIG. 27 is a view showing the hook raise process inthree-dimensional forming;

[0035]FIG. 28 is a view showing the hook raise process inthree-dimensional forming;

[0036]FIG. 29 is a view showing press forming;

[0037]FIG. 30 is a view showing press forming;

[0038]FIG. 31 is a view showing cutting and tool bending after cutting;

[0039]FIG. 32 is a view showing cutting and tool bending after cutting;

[0040]FIG. 33 is a view showing cutting and tool bending after cutting;

[0041]FIG. 34 is a view showing cutting and tool bending after cutting;and

[0042]FIG. 35 is a block diagram showing the arrangement of a controllerfor the spring manufacturing apparatus.

[0043] Other objects and advantages besides those discussed above shallbe apparent to those skilled in the art from the description of apreferred embodiment of the invention which follows. In the description,reference is made to accompanying drawings, which form a part thereof,and which illustrate an example of the invention. Such example, however,is not exhaustive of the various embodiments of the invention, andtherefore reference is made to the claims which follow the descriptionfor determining the scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0044] An embodiment of the present invention will be described indetail below with reference to the accompanying drawings.

[0045] Note that the embodiment described below is an example of meansof implementing the present invention, and can be modified and changedwithout departing from the spirit and scope of the invention.

[0046] [Arrangement of Spring Manufacturing Apparatus]

[0047]FIG. 1 is a perspective view showing the outer appearance of aspring manufacturing apparatus according to this embodiment when viewedfrom the front side. FIG. 2 is a perspective view showing the outerappearance of the spring manufacturing apparatus according to theembodiment when viewed from the rear side. FIG. 3 is a front view of thespring manufacturing apparatus according to the embodiment. FIG. 4 is arear view of the spring manufacturing apparatus according to theembodiment. FIG. 5 is a side view of the spring manufacturing apparatusaccording to the embodiment.

[0048] As shown in FIGS. 1 to 5, the spring manufacturing apparatusaccording to this embodiment includes a regular octagonal table 200which has an opening in its central portion and is mounted on a box-likebase (not shown), a wire feeder 300 placed on the rear surface of thetable 200, and a plurality of tool units 400 arranged on the frontsurface of the table 200 to extend radially around the opening (wireaxis).

[0049] The wire feeder 300 includes a wire feed mechanism 310 forsupplying a wire to be formed into a spring, a wire feed roller pair 320for feeding the wire from the wire feed mechanism 310, and a wire guide330 for guiding the wire pushed out by the wire feed roller pair 320into a spring forming space.

[0050] The wire feed roller pair 320 feeds a wire out of the end portionof a wire insertion hole formed in the wire guide 330 by rotating eachroller in the wire feed direction while clamping the wire with the pairof opposing rollers.

[0051] The wire feed roller pair 320 and wire guide 330 can rotatearound the wire axis to twist a wire while clamping it with the pair ofrollers.

[0052] The tool units 400, at least one tool unit, which form springshaving desired shapes by forcibly bending, curving, winding, or cuttingwires radially extend from the respective sides of the octagon of thetable 200 toward the spring forming spaces while being arranged to beslidable along the wires fed into the spring forming spaces.

[0053] Each tool unit 400 is slid by a corresponding one of crankmechanisms 409 which are arranged at the respective sides of the table200 to convert rotational motions into translational motions and useservo motors as driving sources, and are supported to swing on the rearend portions of the tool units. In addition, if the tool unit 400 has arotating tool that rotates about a tool shaft, a servo motor forrotating the tool shaft is added as a driving source.

[0054] [Tool Unit]

[0055] A curving tool unit 410 for curving the wire fed out from thewire guide 330 as shown in FIGS. 6 to 8, a rotating tool unit 420 forwinding the wire fed out from the wire guide 330 as shown in FIGS. 9 to11, a cutting tool (not shown), and the like are mounted on the table200.

[0056] Each tool unit 400 includes a slider 401 for holding tools T1 andT2, a slide rail 402 for axially supporting the slider 401 to allow itto freely slide or rotate around the tool shaft, and a slide base 403for holding the slide rail 402. The rotating tool unit 420 has arotating shaft 421 for rotating/driving the rotating tool T2 around thetool shaft while slidably supporting the rotating tool T2 with theslider 401, and a servo motor 422 for rotating/driving the drivingshaft.

[0057] The slide base 403 is mounted on the front surface of the table200 such that the slide base can rotate about a shaft hole 404 in whichthe slide mechanism is mounted, and the rotation is restricted by aplurality of elliptic rotation restricting holes 405 symmetricallyformed in two side portions of the middle portion of the base.Protruding shafts formed on the table 200 at positions corresponding tothe rotation restricting holes 405 are movably inserted therein.

[0058] A swing hole 406 for giving a driving force to the tool unit 400to make it swing is formed in the end portion of the slide base 403which is located on the spring forming space side. A roller mounted on aswing ring 450 (to be described later) is inserted into the swing hole406 and clamped with a pair of bridges 407.

[0059] The end portion of the tool unit 400 which is located far fromthe wire fed out from the end portion of the wire guide 330 is rotatablysupported by the shaft hole 404, whereas the end portion of the toolunit which is located near the wire is supported by the swing ring 450which is rotated/driven at a predetermined angle around the wire fed outfrom the end portion of the wire guide 330.

[0060] The tool unit 400 is supported by the shaft hole 404, rotationrestricting hole 405, swing hole 406, and swing ring 450 (to bedescribed later) to swing at a predetermined angle around the wire fedout from the end portion of the wire guide 330.

[0061] Each of these tool units is detachably mounted on the table 200.The types, positions, and the like of tools can be arbitrarily set.

[0062] As the tool units 400, tools other than the above tools, e.g., abending tool, holding tool, and cutting tool can be mounted.

[0063] [Support Structure for Tool Unit]

[0064]FIGS. 12 and 13 are views showing a swing support structure foreach tool unit 400.

[0065] As shown in FIGS. 12 and 13, the annular swing ring 450 forswinging the tool unit 400 is rotatably mounted on the central portionof the table 200 to be centered on the wire, and has a protruding piece451 protruding from a portion of its circumferential portion and a pairof swing rollers 452 that are mounted to correspond to the mountingposition of the tool unit 400.

[0066] The swing ring 450 has an inner ring 450 a and outer ring 450 b.The inner ring 450 a and outer ring 450 b can rotate relative to eachother like a ball bearing. By fixing the inner ring 450 a of the swingring 450 on the central portion of the table 200, the outer ring 450 bis rotatably supported.

[0067] The swing rollers 452 are axially supported on one side surfaceof the swing ring 450 to be rotatable.

[0068] An arm 461 of a driving mechanism 460 placed on the rear surfaceof the table 200 as shown in FIGS. 14 and 15 is coupled to theprotruding piece 451 of the swing ring 450. The swing ring 450 is pushedand pulled by a servo motor 462 to rotate within a restricted range.Upon rotation of this swing ring 450, the tool unit 400 swings at apredetermined angle around the wire fed out from the end portion of thewire guide 330.

[0069] The plurality of tool units 400, each having the swing rollers452 clamped with the bridges 407 in the swing hole 406, simultaneouslyswing upon rotation of the swing ring 450. In addition, when the toolunit 400 is fixed in a bolt hole 408 upon removal of the bridges 407,the swing rollers 452 can freely move within the swing hole 406. In thisarrangement, therefore, when the swing ring 450 rotates, the tool unit400 does not swing. That is, by choosing between clamping the swingrollers 452 with the bridges 407 and not clamping them, all or some ofthe tool units 400 can be supported so as not to swing. This makes itpossible to select tool units 400 which should swing simultaneously.

[0070] According to the above arrangement, the end portions of aplurality of tools are supported such that the tools simultaneouslyswing with respect to the wires fed out from the end portions of thewire guides. These tools can be driven by automatic control usingmotors. This makes it possible to simultaneously make fine adjustmentson a plurality of tool positions with respect to the wires fed out fromthe wire guides by automatic control with high accuracy in a shortperiod of time.

[0071] [Example of Wire Forming by Various Tools]

[0072]FIG. 16 and 17 show rotating tool bending in two-dimensionalforming.

[0073] When rotating tool bending is to be performed in two-dimensionalforming, the rotating tool T2 rotates in the bending direction of a wireW to bend the wire W with its end portion, thereby forming, for example,a hook portion of a spring. In this rotating tool bending, the wire canbe bent without damaging it.

[0074]FIGS. 18 and 19 show tool bending in two-dimensional forming.

[0075] When tool bending is to be performed in two-dimensional forming,opposing tools T3 are slid upward/downward by crank mechanisms to bendthe wire W. This tool bending is used when there is no space for arotating tool.

[0076]FIGS. 20 and 21 show a rotating tool winding process inthree-dimensional forming.

[0077] When a rotating tool winding process is to be performed inthree-dimensional forming, the rotating tool T2 rotates to wind the wireW around its end portion to form, for example, a coil portion of aspring. This rotating tool winding process can form a spring with asmall ratio of the coil outer diameter to the wire diameter. Thisprocess can realize a high-precision coil inner diameter, in particular,and is suited to clutch springs and the like. In addition, the processis suited to forming of wires having cross-sections other than roundcross-sections (e.g., wires having rectangular cross-sections).

[0078]FIGS. 22 and 23 show coiling in three-dimensional forming.

[0079] When coiling is to be performed in three-dimensional forming, thewire W is pushed out to forcibly bring it into contact with the endportion of the abutment tool T1 and wind it on the inclined surface ofthe wire guide 330, thereby forming, for example, a coil portion of aspring. This coiling process can easily change the outer diameter of acoil and facilitate control on the winding angle of the coil. Inaddition, by changing the groove position of the end portion of theabutment tool T1, an initial tensile force and pitch can be easily set.

[0080]FIGS. 24 and 25 show a pitched coiling process inthree-dimensional forming.

[0081] When a pitched coiling process is to be performed inthree-dimensional forming, the wire W is pushed out to forcibly bring itinto contact with the end portion of the abutment tool T1 and wind it onthe inclined surface of the wire guide 330. During this operation, apitch tool T4 is interposed to provide pitches between coil elements,thereby forming, for example, a coil portion of a spring. This pitchedcoiling process allows easy setting of pitches in coil forming.

[0082] FIGS. 26 to 28 show a hook raise processing in three-dimensionalforming.

[0083] In a hook raise process, the hook portion that has already beenformed by the rotating tool T2 or abutment tool T1 by two-dimensionalforming is further bent into a three-dimensional shape by using hookraise tools T5 and T6.

[0084] When a hook raise process is to be performed in three-dimensionalforming, the hook portion obtained by two-dimensional forming by pushingout the wire W and forcibly bringing it into contact with the endportion of the abutment tool T1 is bent into a three-dimensional shape.

[0085]FIGS. 29 and 30 show press forming.

[0086] In press forming, the wire W is clamped between opposing crankbending tools T7 to be formed into a crank-like shape or the like.

[0087] When press forming is to be performed, the opposing press toolsT7 are slid upward/downward by crank mechanisms to clamp and bend thewire W. This press forming is used to form the wire W into a specialshape.

[0088] FIGS. 31 to 34 show cutting and tool bending after cutting.

[0089] When cutting is to be performed, the wire W is clamped betweenopposing holding tools T8 and T9, and a cutting tool T10 is slid to cutthe wire.

[0090] When the cut portion is to be bent, it is done by using therotating tool T2 according to the procedure described with reference toFIGS. 16 and 17.

[0091] As described above, in two-dimensional forming, since one tool isdriven, a fine adjustment on the position of the tool with respect to awire can be automatically made by using the swing support structure.

[0092] In three-dimensional forming, press forming, and other kinds ofspecial forming, since two or more tools are simultaneously driven, if aplurality of tools simultaneously swing, some problems may arise. Forthis reason, some tools may be fixed so as not to swing by removing thebridges 407.

[0093] [Arrangement of Controller]

[0094] The arrangement of a controller for the spring manufacturingapparatus according to this embodiment will be described next.

[0095]FIG. 35 is a block diagram showing the arrangement of a controllerfor the spring manufacturing apparatus.

[0096] As shown in FIG. 35, a CPU 501 controls the overall controller. AROM 502 stores processing contents (programs) of the CPU 501 and variousfont data. A RAM 503 is used as a work area of the CPU 501. A displayunit 504 is used to perform various settings, display the contents ofthe settings, and also display a manufacturing process and the like inthe form of graphs. An external storage device 505 is a floppy diskdrive or the like and used to externally supply a program or storevarious setting contents for wire forming. With this arrangement, forexample, by storing parameters for a given forming process (e.g., for aspring, its free length, diameter, and the like) in advance, springshaving the same shape can always be manufactured by setting the floppydisk and executing the program.

[0097] A keyboard 506 is used to set various parameters. Sensors 507 areused to detect the feed amount of wire, the free length of a spring, andthe like.

[0098] Motors 508-1 to 508-n include a motor for driving the wire feedroller pair 320, a motor for rotating the wire feed roller pair 320 andwire guide 330, and a motor for driving the swing ring. The motors 508-1to 508-n are respectively driven by motor drivers 509-1 to 509-n.

[0099] In this control block, the CPU 501, for example, independentlydrives the respective motors, input/output data to/from the externalstorage device 505, and controls the display unit 504 in accordance withinstructions input through the keyboard 506.

[0100] The present invention is not limited to the above embodiments andvarious changes and modifications can be made within the spirit andscope of the present invention. Therefore, to apprise the public of thescope of the present invention the following claims are made.

What is claimed is:
 1. A spring manufacturing apparatus formanufacturing a spring by feeding a wire to be formed into a spring outof an end portion of a wire guide, and forcibly bending, curving, orwinding the wire by using a tool in a spring forming space near an endportion of the wire guide, wherein a plurality of tools arranged toextend radially with respect to wires fed into the spring formingspaces, supported to be slidable toward the wires fed into the springforming spaces, and supported to allow the end portions of said tools tosimultaneously swing with respect to the wires fed out from the endportions of the wire guides.
 2. The apparatus according to claim 1,wherein said tool has tool support means for supporting said tool toallow said tool to freely slide and/or rotate around a tool shaft, anend portion of the tool support means which is located far from the wireis rotatably supported, and an end portion of the tool support meanswhich is located near the wire is supported by rotating means which isrotated/driven at a predetermined angle around the wire fed out from theend portion of the wire guide.
 3. The apparatus according to claim 2,further comprising driving means for rotating/driving said rotatingmeans by automatic control.
 4. The apparatus according to claim 2,wherein all or some of said plurality of tools can be supported so asnot to swing.